Method for manufacturing shortening



Dec. 27, 1955 D. H. GRIFFIN ETAL METHOD F OR MANUFACTURING SHORTENINGFiled Jan. 4. 1952 a. 2,728,674 Patented Dec. 27, 1955 METHOD FORMANUFACTURING SHGRTENING Application January 4, 1952, Serial No. 264,858

14 Claims. (Cl. 99-118) This invention relates in general to certain newand useful improvements in methods and apparatus for manufacturingshortening and similar high-viscosity liquidssolids dispersions.

In recent years, much effort has been directed to the development andmanufacture of so-called high ratio shortenings; that is to say,shortenings which make possible the formulation of a cake-batter havinga sugarilour ratio in excess of 1:1, without sacrificing volume,texture, and other desirable characteristics in the finished bakedproduct. These l preparations are usually compounded by incorporating asmall amount of some addition agent or agents into hydrogenatedvegetable oils. This is usually accomplished by melting a batch ofh'ardcned oil and stirring in the desired quantity of additive material.Batch processes, however, lack the speed, economy, and precision ofcontrol of continuous processes. Furthermore, most hydrogcnated oilsundergo some slight decomposition when agitated at elevated temperaturesand, as a practical matter, it is, therefore, ditiicult to maintain trueproduct-uniformity from batch to batch. These conventional procedures,moreover, are not readily suitable for treatment of natural animal fats,such as lard, which for reasons of lower price, greater availability,and higher nutritional value are quite desirable particularly incommercial baking. y

It is, therefore, the primary object of the present invention to providemethods and apparatus for the continuous production of high ratioshortening at temperature ranges substantially below the melting pointof the material being treated. 4

It is another object of the present invention to provide methods andapparatus for the production of high ratio shortening at elevatedpressures.

It isa further object of the present invention to provide apparatusofthe type stated which is compact, eflicient, and capable of precisecontrol, so that a uniform product may be continuously produced with aminimum of labor and supervision.

With the above and other objects in view, our invention resides in thenovel features of form, construction, arrangement, and combination ofparts presently described and pointed out in the claims.

In the accompanying drawing- Figure 1 is a schematic drawing showing apreferred form of apparatus embodying the present invention;

Figures 2 and 3 are transverse sectional views taken along lines 2 2 and3 3, respectively, of Figure 1;

Figure 4 is a longitudinal sectional view of the intermixing injectorforming a part of the present invention; and

Figure 5 is a longitudinal sectional viewtaken along line 5-5 ofFigure 1. y

Referring now in more detail and by reference characters to the drawing,which illustrates a preferred embodiment of the present invention, 1designates a conventional heated storage tank from which molten lard maybe drawn throughthe pipe 2, and conventional cut-olf valve or cockwbymeans of a pump 4. The lard preferably may be compounded withconventional quantities of lard flakes and an anti-oxidant. Alsoconnected to the suction side of the pump 4 is a bleeder line 5connected through a rotometer 6 to an air supply line 7, so that a smallcarefully measured quantity of air is injected into the flow of moltenlard as it passes through the pump 4. The pump 4 discharges the moltenlard into the supply line 8 at a pressure of the order of 300 p. s. i.and consequently the airbubbles entrained therein are compressed torelatively minute size. From the supply line 8, the molten lard passesthrough a pressure-responsive control 9 and then through line 10 to acooling worm 11 mounted within a chill-tank 12, which is, in turn,connected by intake and return lines 13, 14, to a supply of cold water.The size of theworrn 11, the rate of ow of hot lard, and the temperatureof the cooling water are so regulated as to lower the temperature of thehot lard while: stillpermitting the lard-air mixture to remainessentially fluid under the` conditions of pressure imposed on it. Fromthe cooling worm 11, the cooled, but still fluid, lard flows throughinlet line 15 into a chilled crutcher i6.. consisting of anelougatedcylindrical shell 17 surrounded by a refrigerated jacket 18 connected toa conventional refrigerant system through a pressure line 19 and suctionline 20. Extending co-axially into the shell 17 througha rotary seal 21is a shaft 22. lnteriorly of the shell 17, the shaft 22 is provided withdiametral arms 23: supporting a pair of obliquely presented scraperblades 24.. In the crutcher 16, the lard is solidified to theconsistency of a heavy paste and the air bubbles are thoroughly dis-lpersed throughout the mass.

The crutcher 16 is connected by a pipe 25 to a iirst blender 26consisting of an elongated vcylindrical shell 27' interiorly providedwith a plurality of radial spines orstationary pickers 28. Extendingco-axially into the shell: 27 through a rotary seal 29 is a shaft 30provided witha plurality of radially projecting rotary pickers 3.1 ar-Vranged to clear the stationary pickers 28. In passing:

through the rst blender 26, the lard-air dispersion is not materiallychanged in temperature or viscosity, but is ap-` preciably smoothed outand rendered homogeneous andV flows outwardly therefrom at a pressure ofthe order of` From the first blender 26, the lard-air dis-- 260 p. s. i.pei-sion passesrthrough a three-way valve 32 and a trans-- fer pipe 33into an intermixing injector 34 consisting of an elongatedlarge-diameter tube 35 provided at one end= with an end-fitting 36having a side-arm inlet 37 for the-v transfer lpipe 33 and at its otherend with an end-cap 381 provided with a co-axial discharge line 39.Projecting co-aXially through the end-tting 36 is an `injection tube 40having a plugged end 41 spaced inwardly a short dis-A -tance from theend-cap 38 and being provided adjacent' its lugged end 41 with aplurality of small-bore apertures 42, all as best seen in Figure 4.

Associated with the apparatus is a pair of open-topped water jacketedkettles 43, 44, conventionally connected to a hot water supply, thekettle 43 being provided with amotor-driven propeller-type agitator 45.ln the kettle is mixed an aqueous dispersion of animal phosphatides,that is to say, phosphatides derived from animal tissue. The.phosphatide-water dispersion is conducted through discharge line 46 to acolloid mill 47 by which it is thoroughly emulsied and is thendischarged through a line 48 to the other water jacketed kettle 44,which is, in

turn, connected through line 49 to a proportioning pump 50 havingitsdischarge line 51 connected through a threeway valve 52 to the injectiontube 43 of the intermixing injector 34. The proportioning pump 50 iscontrolled by the pressure-responsive control 9 to which itis connectedby control-line 53.A This control may be established either byhydraulicpressure or suction in line 53, as may be desired. -In thisconnection, it may be noted that electrical and electronic controls arealso available for establishing cross-control to the proportioning pump.

The rate of ow through the control 9 establishes a directly followingcontrol response through line 53, which causes the proportioning pump 50to transmit a greater or lesser flow of the phosphatide emulsion inaccordance with some predetermined proportional relationship atsubstantially the same or slightly higher pressure as the lard-airdispersion, that is to say, approximately 260-280 p. s. i., so as to bethoroughly interspersed throughout the lard-air dispersion and flow in acommon stream therewith through the transfer pipe 33 to an extrusionchamber 54, having a choked-down exit orifice 55 and a manuallycontrolled valve stem 56 to permit the flowing material to undergo anappreciable degree of turbulence as it ows from the extrusion chamber54, thereby materially improving the homogeniety of the dispersion. Fromthe extrusion chamber 54, the material flows through line 54' directlyinto a second blender 26', substantially identical in all respects tothe first blender 26 and having a rotary shaft 57. At this point, it maybe noted that the shafts 57, Sil, and 22 are all operatively connectedthrough any suitable mechanical transmission means, schematicallyindicated by the dotted line at S, to a suitable motordrive S9. In thesecond blender 26,', the material is finally rendered homogeneous andthe dispersion of lardair, water, and animal phosphatides takes on thecharacteristics of a true emulsion and becomes a finished shorteningwhich is discharged through line 60 into a second extrusion chamber 61,substantially identical with the extrusion chamber 54, and thencethrough a discharge line 62 to a conventional filling machine (notshown).

The three-way valves 32, 52, are employed so that material may berecycled or discharged into open catchbuckets when starting up theapparatus. Thus, it becomes possible to ascertain that a full and normalow of material is passing through the first blender 26 and the line 5lbefore throwing the two streams together in the intermixing injector 34.Consequently, the rst bit of finished product coming through the line 62will conform precisely to the desired quantitative specification.

For purposes of'illustration, and not by way of limitation, thephosphatide-water dispersion preferably consists of approximately thefollowing:

Pints by weight Powdered phosphatides 8-12 Water 35-45 Glyceryl mono anddi stearate 10-15 Emulsilier (glyceryl ester of hydrogenated vegetableons) 10-15 r Lecithin g Preservative (e. g. sodium benzoate), q. s. tomake approximately l/l() of 1% in finished product.

If desired, the lecithin, emulsifier, and glyceryl monoand distearatecan be omitted from the emulsion and instead incorporated in the streamof hot lard by admixture in the tank 1.

After passage through the colloid mill 47, the phosphatide-waterdispersion is reduced to a smooth creamy liquid which does not settleout and by means of the proportion pump 50 from 4 to l0 pounds of thisliquid control in order that the process may be carried out on acontinuous basis at high production rate and with assurance of a highdegree of uniformity in the product.

The finished shortening made by the above described process andemploying the above described apparatus has afweer-1N A Y been found tobe extremely stable. Of utmost importance, however, is the fact thatshortening made in accordance with the present invention is an even moreeffective shortening than any of the conventional so-callcd high ratioshortenings hitherto available, since cakes baked with the shortening ofthe present invention have much greater volume, better texture, andlonger resistance to -staling than cakes baked with conventional highratio shortenings.

While there is described herein a preferred process and arrangement ofapparatus in accordance with the present invention and certain variantsare suggested, nevertheless we do not intend to be limited except by thescope of the appended claims which are to be construed validly asbroadly as the state of the prior art permits.

Having thus described our invention, what we claim and desire to secureby Letters Patent is:

l. The method of converting lard into a high-ratio shortening whichcomprises continuously introducing the lard into a closed system as aflowing stream and, while in said closed system, performing thefollowing steps successively, namely, mixing air With a stream of moltenlard, pumping molten lard-air mixture into a cooling worm at highpressure, passing the lard-air mixture through a chilling Vessel at highpressure and subjecting it to agitation as it passes through thechilling vessel, said lard-air mixture being reduced in temperaturewithin the chilling vessel to such an extent that it loses its liquidityand is reduced to the viscosity of a free-flowing paste, passing thechilled lard-air mixture through a rst agitator at high pressure andbeating in the entrained air to produce a substantially smooth lard-airdispersion, forming a hot aqueous dispersion of animal phosphatides,colloidalizing the aqueous dispersion to form a smooth aqueous emulsion,keeping the emulsion warm, pumping the warm emulsion to form a flowingstream the volumetric rate-of-flow of which is precisely proportionate,at

selected ratio, to the volumetric rate-of-flow of the lardair mixtureinto the cooling worm, injecting the proportioned iiow of the warmemulsion at high pressure into the owing stream of the lard-airdispersion, transmitting the emulsion-'dispersion mixture through anextrusion chamber in which the stream is rendered turbulent, and passingthe emulsion-dispersion mixture through a second agitator to produce asmoothly emulsied shortening.

2. The method of converting lard into a high-ratio shortening whichcomprises continuously introducing the lard into a closed system as aowing stream and, while in said closed system, performing the followingsteps successively, namely, pumping the stream of molten lard into acooling worm at high pressure, passing the lard through a chillingvessel at high pressure and subjecting it to agitation as it passesthrough the chilling vessel, said lard being reduced in temperaturewithin the chilling vessel to such an extent that it loses its liquidityand is reduced to the viscosity of a free-flowing paste, passing thechilled lard through a rst agitator at high pressure, forming a hotaqueous dispersion of animal phosphatides, colloidalizing the aqueousdispersion to form a smooth aqueous emulsion, keeping the emulsion warm,pumping the warm emulsion to form a owing stream the volumetricrate-of-flow of which is precisely proportionate, at a selected ratio,to the volumetric rate-of-ow of the lard into the cooling worm,injecting the proportioned flow of the warm emulsion at high pressureinto the owing stream of the lard, transmitting the emulsion-lardmixture through an extrusion chamber in which the stream is renderedturbulent, and passing the emulsion-lard mixture through a secondagitator to produce a smoothly emulsified shortening.

3. The method of converting lard into a high-ratio shortening whichcomprises continuously introducing the lard into a closed system as aflowing stream and, while in` said closed system, performing thefollowing steps successively, namely, mixing air with the stream ofmolten lard, pumping molten lard-air mixture into a cooling worm at highpressure, passing the lard-air mixture through a chilling vessel at highpressure and subjecting it to agitation as it passes through thechilling vessel, said lard-air mixture being reduced in temperaturewithin the chilling vessel to such an extent that it loses its liquidityand is reduced to the viscosity of a free-flowing paste, passing thechilled lard-air mixture through a first agitator at high pressure andbeating in the entrained air to produce a substantially smooth lard-airdispersion, forming a hot aqueous dispersion of animal phosphatides,colloidalizing the aqueous dispersion to form a smooth aqueous emulsion,keeping the emulsion warm, pumping the warm emulsion to form a flowingstream the volumetric rate-of-flow of which is precisely proportionate,at a selected ratio, to the volumetric rate-of-flow of thelardairmixture into the cooling worm, injecting the propertioned flow ofthe warm emulsion at high pressure into the flowing stream of thelard-air dispersion, and passing the emul-sion-dispersion mixturethrough a second agitator to produce a smoothly emulsified shortening.

4. The method of converting lard into a high-ratio shortening whichcomprises continuously introducing the lard into a closed system as aflowing stream and, while in said closed system, performing thefollowing steps successively, namely, mixing air with lard, subjectingthe lard-air mixture to high pressure, passing the lard-air Vmixturethrough a chillingrvessel at high pressure and subjecting it toagitation as it passes through the chilling vessel, said lard-airmixture being reduced in temperature within the chilling vessel to suchan extent that it loses its liquidity and is reduced to the viscosity ofa free-flowing paste, passing the chilled lard-air mixture through afirst agitator at highpressure and beating in the entrained air toproduce a substantially smooth lard-air dispersion, forming a hotaqueous dispersion of animal phosphatides, colloidalizing the aqueousdispersion to form a smooth aqueous emulsion, keeping the emulsion warm,pumping the warm emulsion to form a flowing stream the volumetricrate-of-flow of 4which is precisely proportionate, at a selected ratio,to the volumetric rate-of-ow of the lardair mixture into the coolingworm, injecting the proportioned flow of the `warm emulsion at highpressure into the flowing stream of the lard-air dispersion,transmitting the emulsion-dispersion mixture through an extrusionchamber in which the stream is rendered turbulent, and passing theemulsion-dispersion mixture through a second agitator to produce asmoothly emulsified shortening.

5. The method of converting lard into a high-ratio shortening whichcomprises continuously introducing the lard into a closed system as aflowing stream and, while in said closed system, performing thefollowing steps successively, namely, mixing' air with`the stream ofmolten lard, pumping molten lard-air mixture into a cooling worm at highpressure, passing the lard-air mixture through a chilling vessel at highpressure and subjecting it to agitation as it passes through thechilling vessel, said lard-air mixture being reduced in temperaturewithin the chilling vessel to such an extent that it loses its liquidityand is reduced to the viscosity of a free-flowing paste, passing thechilled lard-air mixture through a first agitator at high pressure andbeating in the entrained air to produce a substantially smooth lard-airdispersion, injecting a proportioned flow of an aqueous emulsion at highpressure into the flowing stream of the lard-air dispersion,transmitting the emulsion-dispersion mixture through an extrusionchamber in which the stream is rendered turbulent, and `passing theemulsion-dispersion mixture through a second agitator to produce asmoothly emulsifed shortening.

6. The methodof converting lard into a high-ratio shortening whichcomprises. continuously introducing the lard into'a closed system .as aflowing stream and, while in said closedv system, performing thefollowing steps successively, namely, mixing air with the -stream ofmolten lard, pumping molten lard-air mixture into a cooling worm at highpressure, passing the lard-air mixture through a chilling vessel at highpressure and subjecting it to agitation as it passes through thechilling vessel, said lard-air mixture being reduced in temperaturewithin the chilling vessel to such an extent that it loses its liquidityand is reduced to the viscosity of a free-owing paste, passing thechilled lard-air mixture through a first agitator at high pressure andbeating in the entrained air to produce a substantially smooth lard-airdispersion, injecting a proportioned flow of an aqueous emulsion at highpressure into theflowing stream of the lard-air dispersion, and passingthe emulsion-dispersion mixture through a second agitator to produce asmoothly emulsified shortening.

7. The method of converting fatty material of animal origin into ahigh-ratio shortening which comprises continuously introducing the fattymaterial into a closed systern as a flowing stream and, While in saidclosed system, performing the following steps successively, namely,mixing air with the stream of fatty material at a temperature at whichthe fatty material is liquid, pumping air-fatty material mixture into acooling worm at high pressure, passing the air-fatty material mixturethrough a chilling vessel at high pressure and subjecting it toagitation as it passes through the chilling vessel, said air-fattymaterial mixture being reduced in temperature Within the chilling Vesselto such an extent that it loses a substantial degree of its liquidityand is reduced to the viscosity of a freellowing paste, passing thechilled air-fatty material mixture through a first agitator at highpressure and beating in the entrained air to produce a substantiallysmooth dispersion, forming a hot aqueous dispersion of animalphosphatides, colloidalizing the aqueous dispersion to form a smoothaqueous emulsion, keeping the emulsion warm,

pumping tlie warm emulsion to form a flowing stream` the volumetricrate-of-llow of which is precisely proportionate, at a selected ratio,to the volumetric ratc-of-flow of the air-fatty material mixture intothe cooling worm, injecting the proportioned flow of the warm emulsionat high pressure into the flowing stream of the air-fatty materialdispersion, transmitting the emulsion-dispersion mixture through anextrusion chamber in which the stream is rendered turbulent, and passingthe emulsion-dispersion mixture through a second agitator to produce asmoothly emulsified shortening.

8. The method of 'converting fatty material of animal .origin into ahigh-ratio shortening which comprises continuously introducing the fattymaterial into a closed system as a flowing stream and, while in saidclosed system, performing the following steps successively, namely,passing the stream of fatty material through a chilling vessel at highpressure and subjecting it to agitation as it passes through thechilling vessel, said fatty material being reduced in temperature withinthe chilling vessel t0 such an extent that it loses a substantial degreeof its liquidity and is reduced to the viscosity of a free-flowingpaste, passing the chilled fatty material through a first agitator athigh pressure, injecting a proportioned flow of an aqueous emulsion athigh pressure into the flowing stream of the fatty material,transmitting the fatty materialthrough an extrusion chamber in which thestream is rendered turbulent, and passing the mixture through a secondagitator to produce a smoothly emulsified shortening.

9. The method of converting lard into a high-ratio shortening whichcomprises continuously introducing the lard into a closed system as aflowing stream and, while in said closed system, performing thefollowing steps successively, namely, mixing air with the stream ofmolten lard, pumping molten lard-air mixture into a cooling worm at highpressure, passing the lard-air mixture through a chilling vessel at highpressure and subjecting it to agitation as it passes through thechilling vessel, said lardair mixture being reduced in temperaturewithin the chilling vessel to such an extent that it loses its liquidityand is reduced to the viscosity of a free-flowing paste, passing thechilled lard-air mixture through a first agitator at high pressure andbeating in the entrained air to produce a substantially smooth lard-airdispersion, forming an aqueous dispersion of animal phosphatides,colloidalizing the aqueous dispersion to form a smooth aqueous emulsion,pumping the emulsion to form a owing stream the volumetric rate-of-flowof which is precisely proportionate, at a selected ratio, to thevolumetric rate-of-ow of the lardair mixture into the cooling worm,injecting the proportioned ow of the emulsion at high pressure into theflowing stream of the lard-air dispersion, transmitting theemulsion-dispersion mixture through an extrusion chamber in which thestream is rendered turbulent, and passing the emulsion-dispersionmixture through a second agitator to produce a smoothly emulsiedshortening.

10. The method of converting lard into a high-ratio shortening whichcomprises continuously introducing the lard into a closed system as aflowing stream and, while in said closed system, performing thefollowing steps successively, namely, mixing air with the stream ofmolten lard, subjecting the molten lard-air mixture to high pressure,passing the lard-air mixture through a chilling vessel at high pressureand subjecting it to agitation as it passes through the chilling vessel,said lard-air mixture being reduced in temperature within the chillingvessel to such an extent that it losses its liquidity and is reduced tothe viscosity of a free-flowing paste, passing the chilled lardairmixture through a iirst agitator at high pressure and beating in theentrained air to produce a substantially smooth lard-air dispersion,forming a hot aqueous dispersion of animal phosphatides, colloidalizingthe aqueous dispersion to form a smooth aqueous emulsion, keeping theemulsion Warm, pumping the warm emulsion to form a flowing stream thevolumetric rate-of-ow of which is precisely proportionate, at a selectedratio, to the volumetric rate-of-ow of the lard-air mixture, injectingthe proportioned flow of the warm emulsion at high pressure into theflowing stream of the lard-air dispersion, transmitting theemulsion-dispersion mixture through an extrusion chamber in which thestream is rendered turbulent, and passing the emulsion-dispersionmixture through a second agitator to produce a smoothly emulsiiedshortenrng.

11. The method of converting lard into a high-ratio shortening whichcomprises continuously introducing the lard into a closed system as aflowing stream and, while in said closed system, performing thefollowing steps successively, namely, mixing air with the stream ofmolten lard, subjecting the lard-air mixture to high pressure,precooling the lard-air mixture, passing the lard-air mixture through achilling vessel at high pressure and subjecting it to agitation as itpasses through the chilling vessel, said lard-air mixture being reducedin temperature within the chilling vessel to such an extent that itloses its liquidity and is reduced to the viscosity of a free-Howingpaste, passing the chilled lard-air mixture through a first agitator athigh pressure and beating in the entrained air to produce asubstantially smooth lard-air dispersion, forming a hot aqueousdispersion of animal phosphatides colloidalizing the aqueous dispersionto form a smooth aqueous emulsion, keeping the emulsion warm, pumpingthe warm emulsion to form a flowing stream the volumetric Vrate-of-ilowof which is precisely proportionate, at a selected ratio, to thevolumetric rate-of-ow of the lardair mixture, injecting the proportionedflow of the warm emulsion at high pressure into the owing stream of thelard-air dispersion, transmitting the emulsion-dispersion mixturethrough an extrusion chamber in which the stream is rendered turbulent,and passing the emulsion-dispersion mixture through a second agitator toproduce a moothly n in said closed system, performing the followingsteps successively, namely, mixing air with the stream of molten lard,subjecting the lard-air mixture to high pressure, passing the lard-air'mixture through a chilling vessel at high pressure 'and subjecting it toagitation as it'passes through the chillingvessel, said lard-air mixturebeing reduced in temperature within the chilling vessel to such anextent that it loses'its liquidity and is reduced to the viscosity of afree-flowing paste, agitating chilled lard-air mixture While maintainingit under high pressure and beating in the entrained air to produce asubstantially smooth lardair dispersion, forming an aqueous dispersionof animal phosphatides, colloidalizing the aqueous dispersion to form asmooth aqueous emulsion, pumping the emulsion to form a flowing streamthe volumetric rate-of-flow of which is precisely proportionate, at aselected ratio, to the volumetric rate-of-ow of the lard-air mixture,injecting the proportioned flow of the emulsion at high pressure intothe flowing stream of the lard-air dispersion, and passing theemulsion-dispersion mixture through a second agitator to produce asmoothly emulsified shortenmg.

13. The method of converting lard into a high-ratio shortening whichcomprises continuously introducing the lard into a closed system as aflowing stream and, While in said closed system, performing thefollowing steps successively, namely, mixing air with a stream of moltenlard, subjecting the lard-air mixture to high pressure, chilling thelard-air mixture at high pressure and subjecting it to agitation as itis being chilled, said lard-air mixture being thereby reduced intemperature to such an extent that it loses its liquidityrand is reducedto the viscosity of a free-flowing paste, additionally agitating thelard-air mixture at high pressure without materially changing thetemperature thereof and thereby beating in the entrained air to producea substantially smooth lard-air dispersion, injecting a proportionedflow of a lard-free emulsion at high pressure into the flowing stream ofthe lard-air dispersion, extruding the emulsion-dispersion mixture torender the flow thereofiturbulent, and thereafter agitating theemulsion-dispersion mixture without materially changing the temperaturethereof to produce a smoothly emulsified shortening.

14. The method of converting lard into a high-ratio shortening whichcomprises continuously introducing the lard into a closed system as aowing stream and, while in said closed system, performing the followingsteps ysuccessively, namely, mixing air with a stream of molten lard,subjecting the lard-air mixture to high pressure, chilling the lard-airmixture at high pressure and subjecting it to agitation as it is beingchilled, said lard-air mixture being thereby reduced in temperature tosuch an extent that it loses its liquidity and is reduced to theviscosity of a free-flowing paste, injecting a proportioned flow of alard-free emulsion at high pressure into the flowing stream of thelard-air mixture, and agitating the emulsion mixture to produce asmoothly emulsified shortening.

References Cited in the file of this patent UNITED STATES PATENTS1,645,742 Fee, Jr., et al Oct. 18, 1927 2,024,647 Joyce Dec. 17, 19352,062,782 Epstein et al. Dec. 1, 1936 2,330,986 De Haven Miller O ct. 5,1943 2,466,896 Horneman et al Apr. 12, 1949 g FOREIGN PATENTS 9,502Australia Oct. 4, 1932 OTHER REFERENCES Lechithin in Food Processing byAylward, Food Manufacture, July 1952, pages 285-287.

Industrial Oil and Fat Products, Bailey, Second Edition, IntersciencePublishers, Inc., New York, 1951, pages 921924.

1. THE METHOD OF CONVERTING LARD INTO A HIGH-RATIO SHORTENING WHICHCOMPRISES CONTAINUOUSLY INTRODUCING THE LARD INTO A CLOSED SYSTEM AS AFLOWING STREAM AND, WHILE IN SAID CLOSED SYSTEM, PERFORMING THEFOLLOWING STEPS SUCCESSIVELY, NAMELY, MIXING AIR WITH A STREAM OF MOLTENLARD, PUMPING MOLTEN LARD-AIR MIXTURE INTO A COOLING WORM AT HIGHPRESSURE, PASSING THE LARD-AIR MIXTURE THROUGH A CHILLING VESSEL AT HIGHPRESSURE AND SUBJECTING IT TO AGITATION AS IT PASSES THROUGH THECHILLING VESSEL, SAID LARD-AIR MIXTURE BEING REDUCED IN TEMPERATUREWITHIN THE CHILLING VESSEL TO SUCH AN EXTEND THAT IT LOSES ITS LIQUIDITYAND IS REDUCED TO THE VISCOSITY OF A FREE-FLOWING PASTE, PASSING THECHILLED LARD-AIR MIXTURE THROUGH A FIRST AGITATOR AT HIGH PRESSURE ANDBEATING IN THE ENTRAINED AIR TO PRODUCE A SUBSTANTIALLY SMOOTH LARD-AIRDISPERSION, FORMING A HOT AQEOUS DISPERSION OF ANIMAL PHOSPHATIDES,COLLOIDALIZING THE AQUEOUS DISPERSION TO FORM A SMOOTH AQUEOUS EMULSION,KEEPING THE EMULSION WARM, PUMPING THE WARM EMULSION TO FORM A FLOWINGSTREAM THE VOLUMETRIC RATE-OF-FLOW OF WHICH IS PRECISELY PROPORTIONATE,AT SELECTED RATIO, TO THE VOLUMETRIC RATE-OF-FLOW OF THE LARDAIR MIXTUREINTO THE COOLING WORM, INJECTING THE PROPORTIONED FLOW OF THE WARMEMULSION AT HIGH PRESSURE INTO THE FLOURING STREAM OF THE LARD-AIRDISPERSION, TRANSMITTING THE EMULSION-DISPERSION MIXTURE THROUGH ANEXTRUSION CHAMBER IN WHICH THE STREAM IS RENDERED TURBULENT, AND PASSINGTHE EMULSION-DISPERSION MIXTURE THROUGH A SECOND AGITATOR TO PRODUCE ASMOOTHLY EMULSIFIED SHORTENING.